The statements in this section merely provide background information related to the present disclosure. Accordingly, such statements are not intended to constitute an admission of prior art.
Electrically-powered torque machines in the form of multi-phase electric induction motors are employed on powertrain systems to generate propulsion torque as a replacement for or in conjunction with an internal combustion engine. Control of multi-phase, e.g., three-phase electric induction motors can include employing direct (d)-quadrature (q) transformations (abc-dq) to simplify analysis of multi-phase circuits for the motors. This permits reducing three alternating current (AC) quantities to two direct current (DC) quantities for ease of calculations and associated control in the dq reference frame. A stator motor current space vector can be defined in the dq reference frame with orthogonal components along the direct and quadrature axes such that a field flux linkage is aligned along the d-axis and a torque component is aligned along the q-axis. After execution of calculations, an inverse transformation (dq-abc) occurs to determine control commands for operating the motor that can be executed in an inverter. Flux commands are used to determine a direct-current (Id) portion of control in the dq reference frame and torque commands correspond to the quadrature-current (Iq) portion of control in the dq reference frame.